Heat Pump or regular system?

[MediocreButArrogant]

Originally Posted by Squirl

Its an all electric house! Now I am thinking the cost savings isn't significant and the heat pump system is more expensive to buy. So, looks like I'll just do conventional forced air. Even thought its Texas, we do have about 10 days a year of below freezing weather and about 30 days below 45 degrees.

If you came to that conclusion, I'm not sure you understood the replies.

Example: Add 36K BTUs of heat into the house, outside temp is 40F

1) Electrical resistance heating: 100% efficient, takes 10.5 kwh of electricity

2) Heat pump: Assume COP of 3.7 @ 40F, takes around 2.9kwh of electricity to move 36k BTUs of energy from the outside to the inside

The heat pump uses nearly 4x less electricity to heat the house in this example.

When installed w/no gas furnace, it's typical to install a heat pump with electrical resistance panels inside the air handler for emergency heating. These would be used when:

1) Failure of heat pump condenser
2) Temperature so cold outside that heat pump cannot move heat into house fast enough to maintain setpoint
3) High temperature difference between setpoint and current temp, to help close gap faster. My thermostat does this (at our Las Vegas vacation house) when the delta is more than 2 degrees F. The only time this happens is when we turn the heat back on after the house has been empty and the thermostat was set to an away temperature of 55F. Other than that, I've never seen the heat strips kick in.

[CatwomanofV]

We just put in a heat pump in the house we are going to be moving to. Since we haven't been in the house yet, we don't know how well it works and in terms of costs.

You might want to think about geothermal. Yeah it is expensive (so is a heat pump) but you can get 30% tax credit if you put it in before 2016. It is also more efficient than conventional systems or a heat pump. And I heard that the cost to run it is not that much. Unfortunately, we learned the hard way that our heat pump is not eligible for the tax credit.

For me, moving away from dead dinosaurs is the only way to go.


Cat

[MediocreButArrogant]

Originally Posted by CatwomanofV

You might want to think about geothermal. Yeah it is expensive (so is a heat pump) but you can get 30% tax credit if you put it in before 2016. It is also more efficient than conventional systems or a heat pump. And I heard that the cost to run it is not that much. Unfortunately, we learned the hard way that our heat pump is not eligible for the tax credit.

The system you are attempting to describe IS a heat pump, specifically a "geothermal heat pump" or "ground sourced heat pump".

The difference is that the tubes with refrigerant are buried in the ground, or a well, rather than exposed to the air, with a fan blowing over them, as in an air-sourced heat pump. Other than that the concept is the same, which is why they are also called heat pumps.

[CatwomanofV]

Originally Posted by MediocreButArrogant

The system you are attempting to describe IS a heat pump, specifically a "geothermal heat pump" or "ground sourced heat pump".

The difference is that the tubes with refrigerant are buried in the ground, or a well, rather than exposed to the air, with a fan blowing over them, as in an air-sourced heat pump. Other than that the concept is the same, which is why they are also called heat pumps.

Yeah, that's it. We were told that our system is called "Air to Air." Like I said that we were originally going to go with geothermal but decided not to-again, the cost was the factor. We cut some of the expense by not having to dig the wells-but we also didn't get the 30% tax credit either.



Cat

[beach.guy]

As someone with 16+ years in HVAC I agree with K'ledgeBldr.

[Ralph_Kirk]

Has anyone experience with geothermal in the DFW area? How well does it work given the motive soil in these parts? I'm guessing the flexible piping doesn't mind the movement...but is that the case? Do the contractors more often lay the piping vertically or horizontally, and which costs less if the space allows for either?